(a) To ask whether one may carry two Amos on the roof and two Amos on the
column, Rami bar Chama must hold like Rav, in whose opinion, carrying four
Amos on one roof is prohibited, because the roofs forbid each other.

(b) Since a roof has the Din of a Karmelis according to Rav, and the
pillar, a Reshus ha'Yachid, it is obvious that carrying from the one to
the other is prohibited.

(c) His Sha'aleh would then be - whether, since neither a roof of a house
nor that of a porch are fit for habitation, one should be permitted to
carry from one to the other (even if they are owned by two different
owners, and even according to the Rabbanan, who forbid carrying from one
roof-top to the other, because *there* the residents who live underneath
forbid each other to carry, whereas in the case the roof of the porch
there are no residents to forbid); or perhaps, the Din of the roof and the
roof of the porch will be the same as that of two roofs, where carrying
from one to the other is forbidden.

(d) Assuming that carrying from the roof of a porch is permitted, because
there are no residents, Rav Bibi bar Abaye asks what the Din will be with
regard to carrying from the roof of a ruin to the adjoining roof -
underneath, a ruin could be worse, since it is *fit* for habitation
(whereas a porch is not), and Chazal may have decreed carrying from the
roof of an *un-built* ruin to the roof of a house, because of a *built-up*
ruin to the roof. Note: Both a roof, a porch and a ruin have the Din of a
Karmelis.

2)

(a) According to Shmuel, both Rebbi Meir, who considers all roofs one
Reshus, and the Rabbanan, who consider each roof its own Reshus - mean to
permit carrying four Amos but no more.

(b) When Rebbi Meir says 'Reshus Achas le'Chulan' - he means that one is
permitted to carry from one to the other, but only four Amos.

(c) On the previous Daf, Rav forbade carrying from one roof to the other
because of the division of ownership below, so why does he permit it here?

(d) The answer is because there, there is no demarcation on the roof-top
between one roof and the other (as we explained there [see 89a 4c];
whereas here, the roofs are clearly marked, and we will say 'Gud Aseik
Mechitzasah'.

3)

(a) In the previous Sugya, Shmuel permitted carrying on all the roofs
according to the Rabbanan, who hold that each roof is its own Reshus
(because of 'Gud Aseik Mechitzasah'). Consequently, the area of each roof
is less than a Beis Sasayim, in which one is permitted to carry. In our
Sugya, on the other hand, Shmuel is speaking according to Rebbi Meir, who
considers all the roofs to be one Reshus. Consequently, the roofs are
considered to be walled only from the outermost walls, in which case the
area of the roofs is more than a Beis Sasayim, and carrying more than four
Amos is prohibited.

(b) The fact that the houses below are Hukaf le'Dirah, will not help vis-
a-vis the roof above - since the walls of the house below were not built
to incorporate living on the roof.

4)

(a) Shmuel disagrees with Rav, who permits carrying in a boat that is more
than a Beis Sasayim, because it is Hukaf le'Dirah - in *his* opinion, the
walls of a boat are not built to live in, but to keep out the water.

(a) Rav agrees that if the boat is overturned, one is restricted to four
Amos - provided the boat was overturned for technical reasons e.g. to give
it another layer of tar. If the purpose was to sleep under it, then there
is no reason not to be permitted to carry under the entire boat.

(b) Rav Acha b'rei de'Rava quotes the Machlokes between Rav and Shmuel by
a porch in an open field; Rav permits carrying in the entire porch,
because he holds 'Pi Tikreh Yored ve'Sosem' - even by a porch which has no
walls; whereas Shmuel permits only four Amos, because he holds 'Pi Tikreh
Yored ve'Sosem' only when there is at least one proper wall standing, but
not where there are no walls at all.

6)

(a) Rav explains that, Rebbi Meir forbids carrying from a roof-top to a
courtyard - because of a pile in a Reshus ha'Rabim (as we explained above
- 89a).

(b) There is nothing to ask on Rav from the Rabbanan - because, according
to them, it is indeed permitted to carry from a roof-top to a courtyard.

(c) The Gemara does not ask why, even according to *Shmuel*, Rebbi Meir
does not permit carrying from the roof-top to the courtyard? - because
according to Shmuel, the roof-top is considered a Karmelis, whereas the
courtyard (even where there is no Eruv) is considered a Reshus ha'Yachid
(and it is obvious that carrying from one to the other is prohibited).

(b) The reason that the Rabbanan forbid carrying from a roof to an
enclosure, answers the Gemara - is because the roof may break, and be
reduced to less than a Beis Sasayim, transforming it fom a Karmelis to a
Reshus ha'Yachid. And we are afraid that they may just continue to carry
from the one to the other, like they did before.

(c) The Kashya 'Let carrying from the roof-top (less than four Tefachim)
to the enclosure be permitted' (since both, according to Shmuel are
considered a Karmelis) will not apply to Rebbi Meir - who forbids carrying
from above ten Tefachim to below - even in a Reshus ha'Yachid, because of
the decree of 'Tel bi'Reshus ha'Rabim'.

(d) Nor will the Kashya apply according to Rav - since he considers a
single roof-top a Reshus ha'Yachid, and it is obvious that carrying from a
Reshus ha'Yachid to an enclosure (which is a Karmelis) is forbidden.

8)

(a) According to Rav, it is forbidden to carry from a roof to a *small*
enclosure according to the Rabbanan, or from a Chatzer to a Karfaf (even
if it is less than a Beis Sasayim) even according to Rebbi Meir - because
a Karfaf is normally designated for unusual purposes Consequently, Chazal
forbade carrying from a roof or from a Chatzer to it (without an Eruv).

(b) Carrying from a roof to a Chatzer however, or vice-versa, is
permitted, since roofs and courtyards are used for similar purposes.

(c) Rav (according to the Rabbanan) considers a series of roofs a Karmelis
only Lehachmir (to forbid carrying there more than four Amos), but not
Lahakel (to permit carrying less than four Amos from them to a Karfaf) -
in that regard, he considers them a Reshus ha'Yachid, from which one is
forbidden to carry to a Karmelis.

(d) Rav not consider the roofs a full Karmelis, to carry from them into a
ruin or a porch or an enclosure - because a roof is more habitable than a
ruin or a porch or an enclosure.

9)
The reason that the Rabbanan permitted carrying from one enclosure to
another, in spite of the fear that one of them might break and he will
continue to carry there (even though now one of them will have become less
than a Beis Sasayim, and is therefore a Reshus ha'Yachid) - is because, if
one of the enclosures breaks, the broken Mechitzah will be immediately
noticeable that it is now less than a Beis Sasayim, and people will be
careful (unlike on a roof-top of more than a Beis Sasayim, which is not
noticeable unless one is actually standing at the edge of the broken
section of roof, and which therefore justifies the decree - because people
will continue to carry there, just as they did before).